1. Field of the Invention
This invention relates to a driving device having a sealing mechanism, and more particularly, to a device of this type suitable for applying to an apparatus which should be used in a condition without dust and performs a chemical treatment or the like.
2. Description of the Related Art
A washing apparatus for use in a semiconductor wafer manufacturing system is exemplified as an apparatus which should be used in a condition place without dust and performs a chemical treatment.
In the wafer manufacturing system, wafers are subjected to washing in a clean atmosphere without dust so as not to be adversely affected by dust, and are continuously subjected to ammonia treatment, water rinse treatment, hydrofluoric acid treatment, etc.
Conventional washing devices each have a plurality of treatment vessels provided for performing the above treatments, respectively. Wafers are transferred to the vessels by means of a boat or other transfer unit driven by a driving device.
This driving device may cause dust during operation thereof, thereby contaminating a clean atmosphere in which semiconductor wafers are processed. More specifically, the dust may adhere to wafers which are being subjected to fine processing, reducing the yielding percentage of wafer products.
Further, since the driving device is coupled with the movable portion of the above-described transfer unit, it cannot be completely sealed. Thus, ammonia used in the washing device may leak into the driving device, thereby corroding the same.